Airborne radiotelephone communications system

• US 5,519,761 A
• Filed: 07/08/1994
• Issued: 05/21/1996
• Est. Priority Date: 07/08/1994
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gilhousen, Klein S.
• Primary Examiner(s): Bost, Dwayne D.
• Application Number:
  US08/272,061
• Time in Patent Office: 683 Days
• Field of Search: 379/58, 379/59, 379/60, 379/63, 455/9, 455/11.1, 455/12, 455/13, 455/15, 455/33.1, 455/33.2, 455/33.4, 455/54.1, 455/56.1, 455/66
• US Class Current: 455/431
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185

Abstract

The airborne radio communications system of the present invention enables an airborne radio to communicate with the ground based cellular radiotelephone system. The present invention also enables the ground based system to keep track of the location of the airborne radiotelephone and page it when a call from the ground based telephone system is received. The ground base station is connected to upward radiating antennas that form airborne cells. As the aircraft with the radio flies through the airborne cells, the airborne relay receives the signals from the base station and relays them to the radio. If the radio is transmitting signals, the relay transmits those signals, through the airborne cells, to the base station. As the aircraft moves from cell to cell, the radio is handed off to the next cell to maintain communications with the ground.

Claims

1. A communications system comprising:

an airborne based subsystem for transmitting radio signals to, and receiving communication signals having a quality level from, a first base station of a plurality of base stations in a ground based subsystem, and if the quality level of said first base station'"'"'s communication signal is less than a predetermined amount, transmitting the radio signals to, and receiving the communication signals from, a second base station of said plurality of base stations, the airborne based subsystem comprising;

an airborne radio for originating the radio signals and receiving the communication signals, and selecting the second base station in response to the quality level of the second base station'"'"'s communication signal; and

an airborne radio repeater for relaying the radio signals from the airborne radio to the ground based subsystem and for relaying the communication signals from the ground based subsystem to the airborne radio;

the ground based subsystem being coupled to a public switched telephone network (PSTN) and having at least one upward radiating antenna for transmitting the communication signals and receiving the radio signals.

2. The communications system of claim 1 wherein the plurality of upward radiating antennas emits a radiation pattern defining a plurality of airborne cells.

3. A communications system comprising:

an airborne based subsystem for transmitting radio signals to, and receiving communication signals having a quality level from, a first base station of a plurality of base stations in a ground based subsystem, and if the quality level of said first base station'"'"'s communication signal is less than a predetermined amount, transmitting the radio signals to, and receiving the communication signals from, a second base station of said plurality of base stations, the airborne based subsystem comprising;

an airborne radiotelephone for originating the radio signals and receiving the communication signals, and selecting the second base station in response to the quality level of the second base station'"'"'s communication signal; and

an airborne base station for registering the radiotelephone with the ground based subsystem and relaying the radio signals from the airborne radiotelephone to the ground based subsystem and for relaying the communication signals from the ground based subsystem to the airborne radio;

the ground based subsystem being coupled to a public switched telephone network (PSTN), and having a plurality of upward radiating antennas for transmitting the communication signals and receiving the radio signals.

4. The communications system of claim 3 wherein the plurality of upward radiating antennas emits a radiation pattern defining a plurality of airborne cells.